The usefulness of external references to websites is a crucial factor of web-monitoring. It is of high general interest whether your website is visited by the estimated target group or not. This publication measures the value of references of websites by bringing the idea of citation- index to web-analytic tools. The approach presented is considering the number and quality of actions a visitor of a specific website does and the time s/he spent on this website as well as the previous website the user is coming from. The combination of these three parameters are expressed by formulas and afterwards visualized by different tools. Finally this approach is tested and discussed on an existing project. It can be concluded that this concept is indeed useful to get a deeper insight whether external websites addressing the intended target group or not.